catalytic conversion (via soft oxidation) of methane to ethylene
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Catalytic Conversion (via Soft Oxidation) of Methane to Ethylene. Group 5. Agenda. Background Introduction Project Objectives and Production Targets Constraints and Tentative Flow Diagram Safety and Environmental Concerns Market Analysis. Introduction. - PowerPoint PPT PresentationTRANSCRIPT
Catalytic Conversion (via Soft Oxidation) of Methane to Ethylene
Group 5
AgendaBackground IntroductionProject Objectives and Production
TargetsConstraints and Tentative Flow
DiagramSafety and Environmental
ConcernsMarket Analysis
IntroductionWhy we are interested in ethylene and its derivatives? Ethylene is the world’s largest commodity chemical and the chemical industry’s fundamental building block.
Ethylene and its derivatives applications
Introduction Natural gas: is abundant
hydrocarbon feedstock.
Methane: is the principal component of natural gas, has high hydrogen: carbon ratio.
IntroductionCurrent approaches for the direct, large-scale chemical transformation of methane to useful chemicals: aromatization, oxyclorination, and oxidative coupling. Disadvantages: modest selectivity and yield, requirement for corrosive reagents, heat management and temperature control.
New approach???
Sulfur: a soft oxidant for conversion of methane to
ethylene
=> Using gaseous sulfur (S2) as a soft oxidant can hinder the over-oxidation of methane when compared with using O2 as oxidant.
Project ObjectivesWith feedstock as natural gas that
has the same composition in project 1, we study and maximize ethylene production from methane through oxidation conversion.
CHEMCAD would be used as design simulator to assert the process and economic feasibility of the project.
Production Targets
100 molar basis of feed gas: The highest possible recovery
ethylene C2H4. Minimal H2S release to meet
environmental regulation. Minimize the formation of undesirable
byproducts during the conversion of CH4 to C2H4.
High ROI.
Constraints Modest selectivities and yields
Heat management and temperature control
Requirement for corrosive reagents
Dependence on highly toxic halogenated
intermediates
Highly capital-intensive
GENERAL STEPSI. Reaction Site
Soft oxidation of methane with sulfurII. Purification Site
H2S absorption with DEA Regeneration of DEA
III. Separation Site CS2 removal CH4 removal (Recycle back to feed) C2H6 removal
UNIT OPERATIONS Kinetic Reactor Pumps Heat Exchangers MixersAbsorber Distillation Column
TENTATIVE FLOW DIAGRAM
Environmental concernsThree main issues considered when dealing with the production of
ethylene :Global warming Greenhouse gas effects contributed by CS2 and
CH4
Extensive use of land Drilling pads Landscape damageEthylene environmental hazard: C2H4 can cause damage to plants and materials as
a VOC
Health Concerns CS2
Hydrocarbons
H2S
CH3SH
C2H4
Potential acute health effects
-Irritating to eyes, skin and respiratory system- Harmful if swallowed.
-May cause burns or frostbites -Act as a simple asphyxiant
Moderately irritating to eyes and skin- May cause burns or frostbites -very toxic to inhalation
-Irritating to eyes-May causes severe burns or frostbites-very toxic by inhalation
May causes severe burns or frostbites-acts as a simple asphyxiant.
Potential chronic health effects
Behavioral and neuro-physiological changes.-reduced nerve conduction velocity.
Possible damage to heart and central nervous system
Possible damage to lungs, upper respiratory tract, eyes, central nervous system
Possible damage to blood, eyes, kidneys, lungs, livers, and upper respiratory tract.
Possible damage to lungs,heart,Muscle tissue.
Exposure Limits Regulations
OSHA: Occupational safety and Health AdministrationACGIH: American Conference of Industrial HygienistsPEL: Permissible Exposure Limit ; STEL: Short-term exposure limit TWA: Time-weighted average
CS2 Hydrocarbons H2S CH3SH
C2H4
Permissible Exposure Limits (PEL) by OSHA
STEL(1989): -12 ppm, 15 minsTWA (1989): -12 mg/m³, 8 hrs.
-Not available
STEL (1989)-21mg/m3 ,15 min- 15 ppm, 15 min
TWA (2012):-1 mg/m³, 8 hrs-0.5 ppm, 8 hrs
-Not available
Threshold Limit values (TLV) by ACGIH
TWA (2009): -1 ppm, 8 hrs
TWA(2010)-1000 ppm,8hrs
STEL (2010):-5ppm, 15 min TWA (2010)- 1 ppm 8hrs
TWA (2012):-0.98 mg/m³,- 8 hrs. -0.5 ppm8 hrs
TWA(2010):-200 ppm 8 hrs
Safety PrecautionsHIGH CONTROL SYSTEMS
Vibration alarms, toxic gas detectors, combustible gas or fire detectors to potential emergency situations detections
Enclose operations and provide local exhaust ventilation at the site of chemical release.
Provision of fire protection and emergency facilities by additional facilities for emergency shutdown and isolation.
Secondary enclosures (building a vessel around the equipment) for catching leaks for storage or handling of highly toxic materials discharges, or others.
Use of respiratory and protective equipment
Ethylene, Methanol and PropyleneExpanding At A Rapid Pace
Ethylene is the largest of the basic chemical building blocksEthylene, propylene and methanol are expanding at a rapid pace…driven by shale in North AmericaBenzene and chlorine showing more modest growth
Ethylene, Methanol and PropyleneExpanding At A Rapid Pace
2020 Global Capacity:
Ethylene:200 Million Tons
Methanol:160 Million Tons
Propylene:140 Million Tons
Price trend of Ethylene
Demand for Basic Chemicals Driven ByDurable/Non-durable Goods
• Strong economic growthsupports basic chemicaldemand growth• Modest growth in 2012/13suggesting lowerconsumer spending• Emerging markets aredriving tomorrows demandgrowth• China dynamics arechanging, but remainscritical to most markets
Ethylene Investments
North America Ethylene CapacityForecast To Reach 45 Million Metric Tons
Thank you!
QUESTIONS????